1. Field of the Invention
The present invention relates to a car plug which is inserted into a power supply insertion hole formed for a cigarette lighter in an automobile, to supply power to a car stereo, car TV set, air conditioner, various lighting fixtures, etc. In more detail, the present invention relates to a car plug which can be fitted firmly into any power supply insertion hole for a cigarette lighter different in diameter from maker to maker, without coming off even exposed to vibration during driving, etc., and in addition is easy to assemble.
2. Prior Art
In recent years, in the car society, the demand for car plugs of this kind is growing, but conventional car plugs have mostly one or two blades protruded from each body as the protrusion terminal.
However, the inner diameter of the power supply insertion hole formed for a cigarette lighter in an automobile is different from maker to maker of each country, and cars produced in Japan usually use small inner diameters, while those produced in Western countries use large inner diameters. If a car plug with two blades designed and prepared to fit a power supply insertion hole with a small inner diameter formed for a cigarette lighter as in a Japanese car is used in a power supply insertion hole with a large inner diameter formed for a cigarette lighter as in a Western car, it is low in holding capability and stability since it is in resilient contact with the hole only in two directions. So, it frequently occurs that the car plug connected with various apparatuses is loosened to cause contact failure and comes off due to the vibration of driving, and the driver must re-insert it often during driving very dangerously.
In such a case, a match or toothpick, etc., is inserted into the clearance between the power supply insertion hole for a cigarette lighter and the car plug, for preventing it from coming off, and this poses a problem of safety in view of leak and short circuit.